Unless Muhammad Ali was putting on an act yesterday to delude Leon Spinks, hundreds of fans at what the former champ termed his last hard training session before Friday night's title fight saw a 36-year-old fighter past his prime.

Tony Tubbs, a 19-year-old boxer, beat up Ali's face. Afterward Ali said, "I'm feeling a little tired, I ran too much this morning, seven miles. My goal today was defense. I made myself tired talking."

He was unconvincing when he told interviewers, "I probably could have danced and boxed and not got hit, but I want to get used to be jarred in case Spinks has a rally. That is why I take such a good punch."

It was one of Ali's most worst workouts ever and there were taunts from the audience and a plea from one of his corner men, Drew (Bundini) Brown, that brought a nasty exchange. Ali was harsh with the sparring partner, too, but paid for it for taking punches that must have been embarrassing.

Working from a stage in the Municipal Auditorium, Ali built up a drama as he shadow-boxed and members of his entourage seconded everything he said. Then he called to the audience to certify him as "the greatest of all time" as he segued into the famous "Ali Shuffle."

Mocking his critics, Ali said, "They write that I'm too old . . . I can't dance. You're looking at a ghost.

"Ain't I pretty, audience?" ("Yeah") . . . Ain't I nice and lean?" ("Yeah"). Ain't no heavyweight can move like this at 221 pounds."

Ali executed a speedy flurry of punches at his imagined opponent and aroused the spectators.

Brown echoed Ali by shouting, "Mean and lean and fast."

As Tubbs, the young spring partner, came into the ring, Ali pretended to be weeping at the memory of losing the title to Spinks in February. "How did that man whip me?" he asked, feigning utter perplexity. "I want this man (Spinks)."

Ali noticed Tubbs and said, "Here's a brother taller than Spinks, and six years younger. I'm going to put it on him."

The former champion talked casually to the fans while he boxed, as if he were not concerned by Tubbs' efforts. But Ali was seen trying deliberately to block blows, rather than doing it reflexively as he once did. He looked easy to hit. He tried to slip punches by leaning backward casually, but he was too slow. Tubbs outjabbed him to the body and face and beat him to the punch.

"Encourage him," Ali urged the fans between rounds. "Now, I'm going to make him look like a coward in front of all these people."

Then to Tubbs, "You're going to quit first. I'm going to wear you out." But Tubbs continued to beat Ali to the punch. "I'm going to take his manhood in front of all the pretty women out there," Ali remarked to the fans.

At the end of round four, Ali said, "Don't you (Tubbs) jump out of this ring."

"Show us something, champ," someone in the gallery taunted Ali. "Show us some punching."

Brown pleaded, "Come on, champ."

"Shut up, flunky," Ali retorted. "You're my flunky."

Brown snapped back, "Those gloves are your flunkies."

Ali suddenly began to dance and hit Tubbs with two good jabs. But Tubbs, who advanced flat-footed, seemed to walk right through them and began beating Ali about the face again. A handler shouted to Ali, "Thirty seconds left in the round," but instead of flurrying, Ali took a sharp punch to the head and tried to cover his embarrassment by pretending to be staggered.

The master showman then tries to erase the memory of the whole session by clearly falling down without being hit.

There were other sparring partners standing by, but when the sixth round ended, Ali left the ring and went to his dressing room.

He could not have been happy with the exhibition put on with his father, mother and brother in attendance.

Ali seemed weary as he whispered answers to questions in his dressing quarters, occasionally accepting cups of liquid from Dick Gregory, a friend, food faddist, comedian and civil rights activist. Gregory said it was a concoction of lemon, lime and orange juices and "some vitamins."

"I think after the first round or two on Friday night, everybody will think Spinks does not belong in th ring with me . . . I will outclass (him)," Ali said. "It will be no contest. The referee will stop it before it is over. Spinks will get an unmerciful beating . . . he won't be in as good shape as he was the last time. He discos too much."